Management of intermittently closed and open lakes and lagoons

There are about 70  intermittently closed lakes and lagoons (ICOLLs), along the NSW coast.

The Coffs Harbour area has a number of ICOLLs such as Woolgoolga Lake and Hearnes Lake.

ICOLLs alternate between being closed or open depending on rainfall in the catchment and the movement of sand as a result of wave action, tides and winds.

The City of Coffs Harbour manages the ICOLLs in accordance with relevant Coastal Management Programs and has Procedures in place for the management of three of it's ICOLLs where flooding may be a risk, being Woolgoolga Lake, Arrawarra Creek, and Nautilus Creek.

The City has a primarily non-intervention approach to the management of ICOLLs and most of the time it is better to let the ICOLL self-regulate and not artificially open them. Artificially opening ICOLLs can damage the environment and impact aquatic life.

In some situations, where flooding poses a risk and where there is an Estuary Entrance Management Procedure in place, the City may act to scrape the beach berm to lower its height to a particular level. If the ICOLL water level continues to rise it will break out naturally at the pre-determined water level.